A truss device of an escalator or moving walk is a supporting member of an escalator or moving walk, mainly for supporting the functional components like a balustrade or steps of the escalator or moving walk. A truss device generally comprises frame structures at the left and right sides of the escalator or moving walk and soffit sections connecting the left and right frame structures. For some truss device, it may not comprise the soffit sections, and in this case, the truss device means the frame structures at the left and right sides of the escalator or moving walk. Traditionally, the frame structure of the truss device is formed for example by a plurality of angle steel beams welded together which comprises an upper beam and a lower beam extending in the moving direction of the escalator or moving walk, and crossing beams crossing between the upper beam and the lower beam. Such a truss device has its advantage in aspect of load supporting. However it has a disadvantage of high weight and large material cost since it is composed of a plurality of angle steel beams. In addition, for the sake of safety, at least the outer side of the truss device, i.e. the outer side of the escalator or moving walk, is needed to be fitted with decorative panel to wrap the whole truss device to prevent the passengers of the escalator or moving walk touching the inside of the truss device, which makes the weight of the truss device higher and its configuration more complex.
In recent years, a load-supporting device as such is suggested: the load-supporting device is composed of two panels, rather than a plurality of angle steel beams. Particularly, the load-supporting device comprises an outer panel and an inner panel facing the outer panel. The outer and inner panels are connected with each other by connecting means. Such a load-supporting device has its improvements in aspect of reducing the overall weight of the device. However, its capability of load supporting is not sufficient. Thus, there is no report that such a load-supporting device is applied as a truss device of an escalator or moving walk. In addition, if such a load-supporting device is applied as a truss device of an escalator or moving walk, because the load-supporting device is composed of two panels with flat surfaces, then it is not easy to install other functional components on the load-supporting device, that is, it becomes necessary to additionally provide some new components, for example, to weld some supporting components onto the inner panel to support the steps and so on of the escalator or moving walk, which makes the overall structure more complex.
Thus, there exists a need of providing a truss device for an escalator or moving walk, which is light but still has sufficient load-supporting capacity.